Type 1 diabetics may soon be able to power their insulin pumps with an implantable fuel cell instead of relying on single-​use or rechargeable batteries. The power source engineered at ETH Zurich, Switzerland, harnesses the excess glucose from the patient’s tissues to generate electrical energy and control insulin delivery.

The fuel cell is combined with previously developed artificial beta cells that produce insulin at the touch of a button and effectively lower blood glucose levels much like their natural counterparts in the pancreas. An alginate-coated nonwoven fabric encasing the device soaks up body fluid and allows glucose to pass from the tissue into the fuel cell within. The fuel cell anode composed of copper-​based nanoparticles then splits the glucose into gluconic acid and a proton to generate electricity, which sets an electric circuit in motion.

The 0.7 mW/cm², 0.9 V power generated when the fuel cell registers excess glucose is used to stimulate the engineered beta cells to produce and release insulin into the blood. As blood sugar dips to a normal level, the production of electricity and insulin stops.

The fuel cell device described in Advanced Materials can also enable the implanted system to communicate with external devices such as a smartphone. Potential users can adjust the system via a corresponding app, and medical professionals may also access it remotely and make adjustments.

Similar fuel cell technology for powering implantable electronics has also been advanced by MIT researchers.